1. Field of the Invention
The present invention relates to an ink jet printer, and more particularly to an ink jet printer capable of detecting lack of ink.
2. Description of the Related
A conventional ink jet printer is equipped with detecting electrodes, at a cartridge to store ink, for the purpose of detecting lack of ink after exhausted.
The cartridge is emptied, on exhausting ink, to let the air take the place of ink between the two terminals of the detecting electrodes, where lack of ink is detected by increasing resistance.
However, the above conventional method for detecting lack of ink at a cartridge is liable to leak ink at the detecting electrodes arranged at the cartridge, resulting in difficulty of keeping the reliability of the device.
Then, an ink jet nozzle, on exhausting ink, is usually removed as a whole to be replaced by a new one in many personal ink jet printers doing without detection of lack of ink, resulting in the problem of high running costs. On the other hand, the nozzle can be kept, removing only the cartridge, as an alternative, which requires lack of ink to be detected accompanied by the above problem of ink leakage, if detected e.g. at the cartridge, to complicate the structure resulting in high costs.